Most Emission-Efficient Oil Tankers
Ships ranked by AER (Annual Efficiency Ratio) — grams of CO₂ emitted per tonne of deadweight carried one nautical mile (g CO₂/dwt·nm), the IMO carbon-intensity metric behind the CII rating — from official EU MRV emissions data for reporting year 2025. Lower is greener. Pick a segment and size class to see the greenest vessels first.
| # | Vessel | Size (DWT) | Built | Carbon intensity — AER (g CO₂/dwt·nm) | Grade |
|---|---|---|---|---|---|
| 851 |
ECOMAR GARONNE
IMO 1029285
|
49,695 | 2025 |
4.0
|
C |
| 852 |
EAGLE HANOVER
IMO 9398723
|
114,014 | 2010 |
4.0
|
C |
| 853 |
STI SELATAR
IMO 9729245
|
109,999 | 2017 |
4.0
|
C |
| 854 |
ASAHI PRINCESS
IMO 9411197
|
105,372 | 2009 |
4.0
|
C |
| 855 |
UNITY VENTURE
IMO 9773739
|
112,186 | 2017 |
4.0
|
C |
| 856 |
MINERVA ARIES
IMO 9412177
|
105,483 | 2006 |
4.0
|
C |
| 857 |
PSERIMOS
IMO 9578658
|
158,670 | 2011 |
4.0
|
C |
| 858 |
LUNARIA
IMO 9901063
|
111,075 | 2019 |
4.0
|
C |
| 859 |
ASP TREASURES
IMO 9732242
|
115,063 | 2016 |
4.0
|
C |
| 860 |
AMFITRITI
IMO 9419369
|
115,404 | 2009 |
4.0
|
C |
| 861 |
SEBAROK SPIRIT
IMO 9572264
|
109,554 | 2011 |
4.0
|
C |
| 862 |
GHIBLI
IMO 9417799
|
112,961 | 2009 |
4.0
|
C |
| 863 |
STI STABILITY
IMO 9712840
|
109,999 | 2016 |
4.0
|
C |
| 864 |
ANWAAR BENGHAZI
IMO 9888742
|
114,077 | 2021 |
4.0
|
C |
| 865 |
KOS
IMO 1024950
|
115,026 | 2023 |
4.0
|
C |
| 866 |
KING PHILIPPOS
IMO 9601194
|
111,827 | 2012 |
4.0
|
C |
| 867 |
ALFRED
IMO 9826897
|
113,159 | 2018 |
4.1
|
C |
| 868 |
GLORIA MARIS
IMO 9899997
|
156,620 | 2021 |
4.1
|
C |
| 869 |
MINERVA OLYMPIA
IMO 9787194
|
114,780 | 2019 |
4.1
|
C |
| 870 |
CSK VANGUARD
IMO 9728423
|
114,667 | 2013 |
4.1
|
C |
| 871 |
WAVE
IMO 9937012
|
113,841 | 2023 |
4.1
|
C |
| 872 |
KARAVAS
IMO 9420631
|
107,505 | 2010 |
4.1
|
C |
| 873 |
STI KINGSWAY
IMO 9712852
|
109,999 | 2015 |
4.1
|
C |
| 874 |
DUBAI BRILLIANCE
IMO 9422550
|
115,617 | 2011 |
4.1
|
C |
| 875 |
STI GOAL
IMO 9717125
|
109,999 | 2016 |
4.1
|
C |
| 876 |
MAERSK CRETE
IMO 9786190
|
49,919 | 2019 |
4.1
|
C |
| 877 |
AURORA SPIRIT
IMO 9837169
|
129,632 | 2020 |
4.1
|
C |
| 878 |
PETALIDI
IMO 9529475
|
158,531 | 2012 |
4.1
|
C |
| 879 |
JATULI
IMO 9892444
|
112,459 | 2021 |
4.1
|
C |
| 880 |
PHILOTIMOS
IMO 9793997
|
113,247 | 2018 |
4.1
|
C |
| 881 |
IONIC ASPIS
IMO 9523287
|
107,508 | 2011 |
4.1
|
C |
| 882 |
EAGLE PAULINIA
IMO 9858565
|
153,352 | 2020 |
4.1
|
C |
| 883 |
DELTA KANARIS
IMO 9429015
|
157,563 | 2010 |
4.1
|
C |
| 884 |
ANTIPOLIS
IMO 9792204
|
73,981 | 2018 |
4.1
|
C |
| 885 |
LANCING
IMO 9792046
|
104,074 | 2018 |
4.1
|
C |
| 886 |
COPENHAGEN STAR
IMO 9995985
|
115,346 | 2025 |
4.1
|
C |
| 887 |
ALPES
IMO 9817470
|
112,504 | 2018 |
4.1
|
C |
| 888 |
RAYSUT
IMO 9402225
|
99,995 | 2009 |
4.1
|
C |
| 889 |
SUEZ ICE SUPREME
IMO 9296418
|
146,356 | 2007 |
4.1
|
C |
| 890 |
PROPONTIS
IMO 9305623
|
117,055 | 2006 |
4.1
|
C |
| 891 |
ELLIE LADY
IMO 9390173
|
109,999 | 2009 |
4.1
|
C |
| 892 |
PVT POSEIDON
IMO 9457593
|
114,542 | 2006 |
4.2
|
C |
| 893 |
MAERSK CURACAO
IMO 9786205
|
49,919 | 2019 |
4.2
|
C |
| 894 |
ASPEN
IMO 9818058
|
112,459 | 2019 |
4.2
|
C |
| 895 |
FRONT ANTARES
IMO 9745926
|
111,059 | 2017 |
4.2
|
C |
| 896 |
OHIO
IMO 9417440
|
105,188 | 2009 |
4.2
|
C |
| 897 |
MINERVA ZOE
IMO 9800568
|
109,900 | 2019 |
4.2
|
C |
| 898 |
LARGO EAGLE
IMO 9935911
|
49,999 | 2022 |
4.2
|
C |
| 899 |
BUALA
IMO 9433585
|
115,592 | 2010 |
4.2
|
C |
| 900 |
ADVANTAGE PORTOFINO
IMO 9794836
|
75,343 | 2018 |
4.2
|
C |
Which engines power the greenest fleets?
The main engine is the single largest CO₂ source on board — typically well over 80% of a ship's emissions come from propulsion. We aggregated this ranking the other way around: every engine design is scored by the measured carbon intensity of the vessels carrying it, licensee-built units merged under their design brand. The verdict from the 2025 data — modern dual-fuel designs like MAN B&W's ME-GI and WinGD's X-DF families, together with EGR/SCR-abated and ultra-long-stroke G-type engines, consistently power the most emission-friendly ships in service.
AER (Annual Efficiency Ratio) = annual CO₂ emissions ÷ (deadweight × distance sailed), the IMO carbon-intensity metric used for CII ratings. It is built only from measured CO₂, distance and deadweight — not the self-reported cargo transport-work figure, which is unreliable. Implausible outliers (top 2% per segment) are excluded. Grade A–E reflects each vessel's rank within its segment. Source: EMSA THETIS-MRV.